This proposal is submitted in response to RFA ES-99-001, entitled with Superfund Hazardous Substances Basic Research Program. The contamination of soils and drinking water with As and Pb are associated with major public health, remedial, and environmental policy problems. As is found in soil or water at the majority of Superfund sites while Pb is a soil-borne contaminant of concern at approximately 300. This proposal seeks to obtain new knowledge, and train multi-disciplinary pre- and post-doctoral students, concerning the bioavailability of soil Pb in humans, and the bioavailability and/or geochemistry at four Superfund sites in the U.S., two contaminated with Pb and two with As. It also encompasses epidemiologic and geochemistry studies of As in drinking water in Bangladesh which focus on carcinogenic, reproductive and childhood effects of As exposure. We also devote resources to the development of practical remediation strategies for As in wastewater in drinking water. The proposal includes four biomedical research projects: 1) Bioavailability of Soil Pb and As in Humans; 2) Genotoxic Mechanisms of As in Mammalian Cells; 3) A Cohort Study of Aresnicosis in Bangladesh; 4) Environmental As, Pregnancy, and Children's Health. The biomedical research is directly related to that which occurs in three non- biomedical projects: 5) As Mobilization and Bangladesh Groundwater; 6) Redistribution of As at Sites in NF and Maine; and 7) Assessment and Remediation for as Enrichments in Groundwater. The research projects are supported by three Research Support Core Labs: 8) Trace Metals; 9) Geochemistry; and 10) Hydrology An Administrative Core includes an Information Dissemination Program and a Government Liaison & Outreach Program. Finally, a Training Core coordinates multi- disciplinary education and interaction among pre- and post-doctoral trainees support by this proposal as well as other training grant.